Method and means for dispersing fibrous slurries



Sept. 10, 1963 E. J. JUSTUS 3,

METHOD AND MEANS FOR DISPERSING FIBRQUS SLURRIES Filed March 9, 1961 INVENTOR. Edgar c/asfas United States Patent 3,103,463 METHOD AND MEANS F OR DISPERSING FIBROUS SLURRIES Edgar I. Justus, Beloit, Wis., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wisconsin Filed Mar. 9, 1961, Ser. No. 94,587 8 Claims. (Cl. 162-341) established, along the flow path in the head box prior v to deposition of the slurry on the forming surface. While such rolls represent a marked advance over stationary baffles and like means which suflered from the disadvantage of the fibers adhering thereto and ultimately returning to the slurry in the form of massive bundles or flocs, perforated rotary rolls introduce sealing and corrosion problems. As well, it is frequently difficult to attain the desired flow pattern with rectifier rolls and related devices, and it is not unknown even with such structures for the fibers to form clots, flocs or agglomerations which, when deposited on the forming surface, result in undesirable localized irregularities of high density in the forming mat. In some instances, such clots and the like break down the mat, thereby interrupting production.

It is accordingly an important aim of the present in vention to provide stock distributing means which eliminate the named problems connected with perforated rotary rolls and like devices.

Another object of this invention is to provide a head box arrangement for paper machines embodying therein means for establishing and maintaining the fibrous particles substantially uniformly distributed in the liquid portion of the slurry.

Still another object of this invention is to provide novel means for producing successively smaller scale turbulence in a fibrous slurry, resulting in uniform distribution of the fibers therein without substantial increases in the formation of clots or agglomerations.

A further object of the instant invention lies in the pro vision of stock flow distributing means eliminating the sealing and corrosion problems associated with rectifier rolls, and which further deliver the stock slurry to the forming surface of a paper machine under conditions of minimum large scale flow turbulence,-minimum gross secondary flow patterns and substantially uniform mean velocity, wherein fiber distribution is markedly improved.

An even further object of the present invention is to provide means for controlling the conditions of flow of a stock stream immediately prior to its delivery to the forming wire of a Fourdrinier type paper machine.

Yet a still further object of this invention lies in the provision of apparatus for dispersing particulate material in a liquid medium, comprising means for generating small scale turbulence in the liquid medium to disperse the particulate material, and means for vibrating the turbulence generating means to prevent the adherence of particulate material thereto. 1

And a still further object of the instant invention is to provide a method of delivering stock to the forming surface of a paper machine in a condition of uniform mean velocity with minimum amounts of large scale turbulence and gross secondary flow patterns, which includes flowing the stock past a series of abutments sized to create successively smaller scale turbulent patterns in the flowing stock and each one spaced in the wake from the one ahead, and vibrating the abutments to prevent fibers from adhering thereto.

Other objects andadvantages of the invention will become more apparent during the course of the following description, particularly when taken in connection with the accompanying drawings.

In the drawings, wherein parts throughout the same:'

FIGURE 1 is a side elevational view, withparts thereof taken in section, showing apparatus constructed in accordance with the principles of this invention;

FIGURE 2. is a sectional view taken along the line II.II of FIGURE 1;

FIGURE 3 is a fragmentary side elevational view of a turbulence generator and showing one means for vibratlike numerals designate like ing the same to prevent the adherence of stock fibers; I

FIGURE 4 is a fragmentary side elevational view, with parts thereof in section, and showing another form of turbulence generator with means connected thereto for I effecting vertical vibration; and

FIGUREv 5 is a fragmentary sectional View showing particularly means for resiliently mounting the turbulence generators in the wall structure of a head or flow box. Stated briefly, a high order of particle dispersion throughout a liquid vehicle in the flow box of a paper machineis achieved by bridging the inlet to the flow box with a first series of submerged turbulence generators,

bridging the stock outlet with a third series of submerged turbulence generators, locating in spaced relation to the first and third series of turbulence generators a second series of abutments or turbulence generators, and vibrating one or all of the series of turbulence generators to prevent the adherence of the particles thereto. The turbulence generators in each series are particularly sized and spaced with respect to the other abutments so that there is created successivelyfiner scale turbulence of a high order intensity in the liquid vehicle or medium.

The turbulence generators are mounted by the wall structure of the flow box by resilient support means additionally providing minimum cost and highly eflicient seals. The vibrating means for'the turbulence generators tak-e diverse forms, the vibration is of a high frequency and low amplitude, and the vibration is preferably eifecte d transverse to the local flow of slurry. Other features of the instant invention will become apparent as the description now proceeds.

Referring now first to FIGURES 1 and 2, there is shown a flow box or head box generally designated by the numeral 10 and which is provided with an inlet 11 of any desired construction for introducing stock into the head box 10 and from which the stock flows onto a forming wire 12 trained about a breast roll 13 in the manner well known in a Fourdrinier paper machine. The head box 10 is shaped at its outlet end top rovide a slice 14 through which the stock flows onto the forming wire 12, a web W ultimately being formed thereon in the conventional manner.

The flow box 10 may be either of an open top construction, or may as shown, be provided with a top or upper wall 15, opposed side Walls 16 and '17, bottom wall 18 terminating in a forward apron portion 18a, a rear wall 19 and a front wall 20. The forward apron portion 18a is shown to be tapered at its forward end and terminates generally at the top center of the breast roll 13, so that the stock flowing thereover from the inlet box 10 may flow onto the upper wire run 12a while the wire is supported ina substantially horizontal plane by the breast roll 13 and conventional Fourdrinier machine structure.

. The floor or bottom wall 18, side walls 16 and 17,

rear wall 19 and'front wall 20 cooperatively define the substantially 3, stock pond or chamber wherein stock S is flowed from the inlet 11 to the outlet 14 under a pressure gradient. The force driving the stock through the outlet 14 is primarily a hydraulic force exerted by the stock at said outlet. This hydraulic force is determined by the hydraulic head of the stock in the inlet 11, and by the pressure on the top of the stock.

In accordance with the principles of this invention, there is positioned in the stock flow channel defined by the head box 10 a first series or bank of vibratory abutments or turbulence generators 25 extending transverse of the direction of flow of the slurry S across the full width of the flow channel, and preferably curved or arcuately formed so as to bridge the stock fiow inlet 11 and thereby increase the intensity and reduce the scale of turbulence in the slurry essentially immediately upon its entry into the headbo'x 10. The abutments 25 desirably are in the form of equi-distantly spaced and parallelly arranged cylindrical rods symmetrically located about the longitudinal centerline of the flow channel, and shaped as shown to not only bridge the stock flow inlet 11, but to also be essentially entirely covered by the stock pond. In other words, as appears in FIGURE 1, all turbulence generators are submerged in the flowing stock. Generally stated, the curved abutments 25 are sized relative to the width of the channel so as to occupy about 50% of said width.

Each of the opposite ends of the turbulence generators is threaded to receive thereon fastening means 26 which may take the form of nut means, and the abutments at their opposite ends are received in resilient mounting blocks 27 attached by screw means 28 in general conical apertures 24 in the bottom and end walls 18 and 19 of the flow box 10. In this manner, any possibility of leakage is effectively prevented, and there is eliminated the sealing v and corrosionproblems associated with the conventional rectifier rolls.

Rectifier rolls, even when rotated, present a further problem of fibrous material adhering thereto. As well, the abutments 25 provide surfaces to which may cling stock fibers, even though the abutments are smooth cylindrical members. Such clinging fibers often break loose from the rods in the form of relatively large bundles or flocs, causing at least undesirable localized irregularities of high density in the forming mat, and even breakdown of the mat with consequent production interruptions.

To prevent the occurrence of such conditions, the turbulence generators 25 are, by this invention, vibrated at a high frequency and low amplitude. For this purpose, each of the cylindrical rods 25 has welded or otherwise secured thereto a transversely extending connecting rod 29 to which is welded or otherwise afiixed a generally vertically extending actuating rod 30 received in a vibrator head 31 reciprocated by motive means 32. The vibrating head is movable in opposite vertical directions within a suitable aperture in the top wall 15 of the flow box 10', and in this manner the turbulence generators 25 are either intermittently or continuously vibrated in their rubber mounts 27 to prevent fibrous material from clinging to the generators. The generators are thereby maintained in a continuously clean condition.

The abutments 25, as was earlier stated, are spaced to provide a total flow area therebetween approximating 0% of the width of the flow channel. Variations may of course be practiced therein, and the total flow area between the abutments may lie within the range of from to 90%. Further, the ratio of the cross-sectional dimension of each abutment 25 to the distance from the center of one abutment to the center of an adjacent abutment is desirably equal to one-half. A ratio'less than that indicated does not produce downstream turbulence sufiicient for proper stock dispersion, whilea ratio substantially greater than one-half'produces undesirable jetting velocities through the open area between the abutments.

Located downstream fromthe first'bank of abutments 25 a controlled distance is a second bank of turbulence generators or abutments 35. This distance may be from about two to about five times'the distance from the center of one abutment 25 to the center of an adjacent abutment 25, or as may be otherwise stated, the distance of the second bank of abutments 35 from the first bank of abutments 25 is greater than the distance to the zone of maximum intensity of the first order flow turbulence created in the slurry by the first bank of abutments 25, but less than the distance from the first bank of abutments where a uniform mean flow occurs. Thus, while the turbulence intensity depends upon velocity of stock flow, and the distance between the first and second bank of abutments is therefore dependent on velocity, when the distance between the first and second banks is substantially greater'than five times the distance between the centers of the abutments 25, the turbulent flow generated in the slurry by the first abutments 25 tends to dissipate or decay and to merge into a uniform mean flow pattern. This is to be avoided.

It may be observed from FIGURES 1 and 2 that the abutments 35 of the second bank are of a lesser diameter and a reduced spacing from their centers, as compared with the first bank of abutments 25. By this arrangement, and when the second bank is located from about two to :about five times the distance from the centers of the first abutments 25, a second order of eddy currents greater in number but lesser in magnitude than the first order eddy currents from the first bank 25 are generated in the slurry passing through the open area between the second bank of abutments 35. This second order of eddy currents tends to further distribute and disperse the fibers throughout the slurry, while the amplitude of the second order eddy currents is reduced relative to the amplitude of the first order eddy currents. As with the first bank of abutments 25, the abutments in the second bank 35 are sized and spaced to provide a total open flow area in the second bank approximating 50% of the width of the channel.

The abutments 35 in the second bank also present a problem of fibrous material adhering thereto, and accordingly, the second bank is also vibrated to maintain the abutments in'clean condition. At the upper ends of the abutments 35, or inwardly of the opposite ends thereof, the abutments 35 are connected by a transversely extending rod member 36 to which is attached an actuating II'Od. 37 connected to -a vibrating head 38 reciprocated under action of motive means 39. The lower end of each abutment 35 is received in resilient mounting means 40 and is engageable therewith by nut means or the like 4 1 threaded onto the lower end of each rod. The mountin'g block 40 is attached to the bottom wall 18 by screw means 42, and as earlier described in connection with the mounting blocks 27,'eaoh block 40 is shaped to mate with an aperture 43 in the head box bottom wall 18. The abutments 35 are in this manner continuously vibrated transverse to the local flow of slurry at a high frequency and low amplitude, so as to maintain the abutments continuously free of adhering fibers.

The slurry, in this fine scale turbulent condition, is then flowed past a third bank of abutments 45 spaced from the second bank 35 a distance calculated in the manner earlier described. It is to be observed that the abutments or turbulence generators 45 are arcuately formed so :as to span the stock outlet 14, thereby providing control of stock turbulence immediately prior to its issuance from the slice lip and onto the upper reach 12a of the forming wire 12. Of course, the third bank of abutments 45 should be spaced upstream from the outlet a distance sufiicient to permit a partial decay of the turbulence generated by the abutments 45, whereby the slurry is delivered to the outlet with the fiber content thereof in :a uniformly Well-dispersed state.

To increase dispersion or distribution of the fibers in the slurry by generating a still finer scale turbulence, each lower end in a rubber block or the like are provided with of the abutments 45 in the final or third bank of abutments is preferably of the minimum size permissible in terms of structural strength and the like. The abutments 45 are mounted by the fiow box wall structure in generally the manner of the first bank of abutments 25, and accordingly, like numerals have been applied with the sufiix "a appended thereto. However, in FIGURE the configuration of the mounting arrangement is more clearly illustrated, and it will be noted therefrom that the resilient block member 27a is shaped to provide a generally conical plug or body portion 46 contoured to snugly fit in the wall aperture 24a, the mounting block 27a further including a plate-like flange portion 47 lying flush against the front wall 20 of the flow box 1t) and being passaged to receive the fastening means 28a.

In order to maintain the abutments 45 of the third bank of turbulence generators in a continuously clean condition free of adherent fibers, the abutments 45 are also vibrated in accordance with this invention. 'It may be seen from FIGURE 1 that the structural arrangement for vibrating the abutments 45 corresponds essentially identically to the vibrating apparatus for the first bank of abutments 25, and accordingly, the sufiix a appended thereto have been applied to the connecting rod 29a, actuating rod 30a, vibrating head 31a and motive means 32a. Of course, as will now be noted, any of the abutments 25, 35 and 45 may be vibrated by other means.

Referring now to FIGURE 3, one abutment 5d of a bank or array of turbulence generators is received at its 51 and is attached thereto by nut means 52. The rubber block 51 is attached to bottom wall 18 by screw means 53', and at its upper end the abutment 50 is attached by welding techniques to a crank arm 54 mounted by a transversely extending rod member 55 received at opposite ends in the side walls of the flow box. A turning force applied to the transverse rod 55 pivots the crank arm 54, to thereby vibrate or oscillate the abutment 50 in a generally perpendicular direction. All abutments in a tank or array the crank arms 54, and the crank arms are mounted upon a single transversely extending rod 55.

It has been noted herein that cylindrical rods provide the preferred form of turbulence generators, although screens or perforated plates may be used in lieu thereof. This appears in FIGURE 4, wherein it may be noted that a transversely extending platemember 60 provided wtih apertures 61 therein has formed at its lower end an inverted generally T-shaped portion 62 engaged by a yoke member 63 which is vibrated by any suitable means of either the mechanical or electrical type. The plate member 69 vibrates or reciprocates within a rubber block member 64 suitably slotted and attached by screw means or the like 65 to the bottom wall 18 of the flow box. The plate member 60 may be arcuately formed in the manner of the .abutments 25 and 45, and if desired the vibratory means may be connected to the plate member 60 in the manner shown with respect to the rods 25, 35 and 45 in FIGURE 1. Of course, the plate means 66 extends between opposed side walls of the flow box and may thereby brace or rigidify the head box.

Different forms of turbulence generators have been disclosed and described herein, as well as various means for vibrating the same. It is aecordinglybelieved quite apparent that the invention is susceptible of numerous modifications without departure from the novel concepts thereof.

I claim as my invention:

1. In apparatus for supplying a stock slurry in a uniformly dispersed state to a forming surface in a paper machine, comprising a head box having a stock inlet and stock outlet, a first row of transversely spaced rod members, said row of rod members extending across the width of the head box and bridging the inlet thereof for generating turbulence of a first order magnitude in the slurry like numerals with predetermined size to disperse the stock therein, a second row of transversely spaced rod members, said now of rod members extending across the :width of the head box and located downstream from said first row for generating turbulence of a lesser order of magnitude to fiurther disperse the stock in the slurry, a third row of transversely spaced rod members, said now of rod members extending across the Width of the head box [and bridging the outlet thereof for generating turbulence of an even lesser magnitude to even further disperse the stock in the slurry, the improvement comprising resilient block means receiving the lower ends of the nod members and attached to .the floor of the head box, bar means interconnecting the rod members in each row, actuating means connected to said bar means, and motive means connected to said actuating means to reciprocate the actuating means and vibrate the rod members to prevent stock from clinging thereto.

2. Apparatus for distributing fibers in a stock slurry for delivering of the slurry to the forming surface of a paper making machine, which comprises first means for generating a first uniform pattern of small scale turbulence of a first order magnitude. in the stock slurry for distributing the fibers therein, second means downstream from the first means for generating a second uniform pattern of smaller scale turbulence in the slurry for further distributing the fibers therein, said first means comprising a multiplicity iof abutments extending transversely to the stock flOlW with each abutment presenting a turbulence generating land area of predetermined size between open areas accommodating stock flow and said second means com prising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of substantially less than said areas accommodating stock flow, the total number Olf land areas and open areas in said second means being substantially greater than in said first means, whereby the slurry is delivered to the tfiorming surface of the paper making machine with fibers uniformly and well dispersed throughout the slurry, and means for vibrating the abutments of said first and second means generally perpendicularly to the direction of how and to the cross machine 7 direction to prevent the adherence of stock fibers thereto.

3. Apparatus for delivering a stock slurry to the forming surface of a paper making machine in a condition exhibiting substantially uniform fiber distribution in the slurry, which comprises means for flowing the slurry along a path to the forming surface of the paper making machine, first means for generating a first uniform pattern of small scale turbulence of a first order magnitude in the slurry to distribute the fibers therein, second means located downstream of the first means in the turbulent wake of the slurry and in a flow path area where the first uniform pattern of turbulence is in a condition of partial decay for generating a second uniform pattern of smaller scale turbulence in the slurry whereby the fiber distribution in the slurry is increased, said first means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of predetermined size between open areas accommodating stock flow and said second means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of substantially less than said predetermined size between substantially smaller open areas accommodating stock flow, the total number of land areas and open areas in said second means being substantially greater than in said first means, means for receiving the slurry downstream of said second means for delivery For \the stock slurry in a condition of partial turbulence decay to the forming surliace of the paper making machine, and means for vibrating the aforesaid abutments generally perpendicularly to the direction of stock flow and to the cross machine direction to prevent adherence of fibers thereto.

between substantially smaller open 4. Apparatus 'for delivering a stock slurry to the forming surface of a paper making machine in a condition exhibiting substantially uniform fiber distribution which comprises a first bank of abutments extending transversely in the flow path of the slurry for generating a uniform pattern of small scale turbulence in the slurry to thereby distribute the fibers in the slurry, at least one additional transverse bank of abutments downstream of the first bank of abutments, the ialbutments in said second b ank being of substantially lesser size than the abutments in said first bank of abutments for generating a second uniform pattern of small scale turbulence in the slurry, said second bank of abutments being located in an area of the flow path where the first uniform pattern of turbulence is in a condition of partial decay, the abutments in each of said banks presenting a multiplicity of turbulence generating land areas with a multiplicity of open area therebetween to accommodate stock flow, means for guiding the slurry to the forming surface of the paper making machine downstream from the aforesaid bank whereby the slurry is delivered [to the forming surface While the slurry turbulence is in a condition of partial decay, and means [for vibrating the aforesaid abutments generally perpendicularly to the direction of flow [and to the cross machine direction to prevent adherence of fibers thereto.

5. Apparatus for delivering a stock slurry to the forming surface of a paper making machine in a condition exhibiting substantially uniform fiber distribution in the slurry, which comprises a first transversely extending bank of a multiplicity of spaced abutments located in the flow path of the stock for generating a uniform pattern of small scale turbulence of a first order of magnitude in the slurry, the abutments in the first bank being relatively small sized and substantial in number to occupy from about 10% to about 90% of the cross sec- 7 tional area of the slurry flow path, at least one second transversely extending bank of abutments located a distance approximately equal to from two to about five times the distance between the center-to-center points of a pair of adjacent abutments in the first bank whereby the second bank of abutments are located in the tubulent wake of the first bank of abutments, the abutments of said second bank being substantially greater in number than and substantially smaller in size than those of the first bank for generating a uniform pattern of smaller scale turbulence in the slurry, the aforesaid abutments terminating abrutply at the off-running sides in the direction of stock flow whereby collection of stock fibers at the oncoming sides is minimized and wakes of non-streamline flow are created at the off-running sides, means for guiding the flow of slurry to the forming surface of the paper making machine to permit partial decay of the turbulence before delivery of the slurry to the forming surface, and means for vibrating the aforesaid abutments generally perpendicularly to the direction of flow and to the cross machine direction to prevent the adherence of fibers thereto.

6. Apparatus for distributing fibers in a stock slurry for delivering of the slurry to the forming surface of a paper making machine, which comprises first means for generating 'a first uniform pattern of small scale turbulence of a first order magnitude in the stock slurry for distributing the fibers therein, second means downstream from the first means for generating a second uniform pattern of smaller scale turbulence in the slurry for further distributing the fibers therein, said first means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of predetermined size between open areas accommodating stock flow and said second means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of substantially less than said predetermined size between substantially smaller open areas accomodating stock flow, the total number of land areas and open areasin' said second means being susbtantially greater than in said first means, whereby the slurry is delivered to the forming surface of the paper making machine with fibers uniformly and well dispersed throughout the slurry, resilient means mounting said first means and second means for generating turbulence, and drive means cooperating with said resilient means to vibrate said first and second means for generating turbulence generally perpendicularly to the direction of flow and to the cross machine direction to minimize adherence of stock fibers thereto.

7. Apparatus for distributing fibers in a stock slurry for delivering of the slurry to the forming surface of a paper making machine, which comprises first means for generating a first uniform pattern of small scale turbulence of a first order magnitude in the stock slurry for distributing the fibers therein, second means downstream from the first means for generating a second uniform pattern of smaller scale turbulence in the slurry for further distributing the fibers therein, said first means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulance generating land area of predetermined size between open areas accommodating stock fiow and said second means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of substantially less than said predetermined size between substantially smaller open areas acommodating stock flow, the total number of land areas and open areas in said second means being susbtantially greater than in said first means, whereby the slurry is delivered to the forming surface of the paper making machine with fibers uniformly and Well dispersed throughout the slurry, resilient means mounting said first means and second means for generating turbulence, and drive means cooperating with said resilient means to vibrate said first and second means for generating turbulence generally perpendicularly to the direction of flow and to the cross machine direction to minimize adherence of stock fibers thereto, said first means and said second means for generating turbulence each consisting essentially of a generally transversely extending bank of cylindrical, generally parallel, equally spaced rods occupying substantially 50% of the total transverse area.

8. Apparatus for distributing fibers in a stock slurry for delivering of the slurry to the forming surface of a paper making machine, which comprises first means for generating a first uniform pattern of small scale turbulence of a first order magnitude in the stock slurry for distributing the fibers rtherein, second means downstream from the first means for generating a second uniform pattern of smaller scale turbulence in the slurry for further distributing the fibers therein, said first means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of predetermined size between open areas accommodating stock flow and said second means comprising a multiplicity of abutments extending transversely to the stock flow with each abutment presenting a turbulence generating land area of substantially less than said predetermined size between substantially smaller open areas accommodating stock flow, the total number of land areas and open areas in said second means being substantially greater than in said first means, whereby the slurry is delivered to the forming surface of the paper making machine with fibers uniformly and well dispersed throughout the slurry, resilient means mounting said first means and second means for generating turbulence, and drive means cooperating with said resilient means to vibrate said first and second means for generating turbulence generally perpendicularly to the direction of flow and to the cross machine direction to minimize adherence of stock fibers thereto, said first means and said second means for generating turbulence each consisting essentially of a generally transversely extending bank of cylindrical, gen- 9 erally parallel, equally spaced :rods occupying substantially 50% of -the total transverse area, with the second bank being spaced downstream from the first bank a distance approximately equal to 2 to 5 times the center-to-center distance between adjacent rods in the upstream bank of rods.

References Cited in the file of this patent UNITED STATES PATENTS 10 Stewart June 12, 1956 Boone et al. Apr. 29, 1958 Johnson et al Apr. 14, 1959 FOREIGN PATENTS Germany June 27, 1931 Sweden Nov. 9, 1943 Great Britain Oct. 16, 1957 OTHER REFERENCES Pulp and Paper Making Notes, Scott Paper Company,

Chester, Pennsylvania (1956), pp. 204, 205. (Copy in Division 25.) 

1. IN APPARATUS FOR SUPPLYING A STOCK SLURRY IN A UNIFORMLY DISPERSED STATE TO A FORMING SURFACE IN A PAPER MACHINE, COMPRISING A HEAD BOX HAVING A STOCK INLET AND STOCK OUTLET, A FIRST ROW OF TRANSVERSELY SPACED ROD MEMBERRS, SAID ROW OF ROD MEMBERS EXTENDING ACROSS THE WIDTH OF THE HEAD BOX AND BRIDGING THE INLET THEREOF FOR GENERATING TUBULENCE OF A FIRST ORDER MAGNITUDE IN THE SLURRY TO DISPERSED THE STOCK THEREIN, A SECOND ROW OF TRANSVERSELY SPACED ROD MEMBERS, SAID ROW OF SAID MEMBERS EXTENDINGG ACROSS THE WIDTH OF THE HEAD BOX AND LOCATED DOWNSTREAM FROM SAID FIRST ROW FOR GENERATING TUBULENCE OF A LESSER ORDER OF MAGNITIDE TO FURTHER DISPERSE THE STOCK IN THE SLURRRY, A THIRD ROW OF TRANSVERSELY SPACED ROW MEMBERS, SSAID ROW OF ROD MEMBERS EXTENDING ACROSS THE WITH OF THE HEAD BOX AND BRIDGING THE OUTLET THEREOF FOR GENERATING TUBULENCE OF AN EVEN LESSER MAGNITUDE TO EVEN FURTHER DISPERSE THE STOCK IN THE SLURRY, THE INPROVEMENT COMPRISING RESILIENT BLOCK MEANS RECEIVING THE LOWER ENDS OF THE ROD MEMBERS AND ATTACHED TO THE FLOOR OF THE HEAD BOX, BAR MEANS INTERCONNECTING THE ROD MEMBERS IN EACH ROW, ACTUATING MEANS CONNECTED TO SAID BAR MEANS, AND MOTIVE MEANS CONNECTED TO SAID ACTUATING MEANS TO RECIPROCATE THE SCTUATING MEANS AND VIBRATE THE ROD MEMBERS TO PREVENT STOCK FROM CLINGING THERETO. 